Synergistic Effect of Amino-Modified Co-MOF and APP on Improvement of the Fire Safety of the Rigid Polyurethane Foam

The combustion of rigid polyurethane foam (RPUF) generates significant amounts of toxic and high-temperature smoke, which restricts its application. Here, an amino-modified Co-MOF (NH2–Co-MOF) was synthesized and it was used in conjunction with ammonium polyphosphate (APP) to decrease the flammability of RPUF. We obtained the expected results: the fire safety of RPUF was greatly enhanced by the addition of NH2–Co-MOF and APP. Compared to neat RPUF, the peak heat release rate (pHRR) and total heat release (THR) values of N–C/A/RPUF decreased by 22.5 and 37.4%, respectively. Based on the analysis of combustion products of the gaseous and condensed phases, it can be seen that the synergistic use of NH2–Co-MOF with APP enhances the barrier effect, dilutes combustible gases, and quenches the combustion chain reaction.